This invention relates broadly to the art of sheet feeding devices, and more specifically is a continuation-in-part of U.S. patent application Ser. No. 569,989, filed on Apr. 21, 1975 by Wilbur J. Morrison and Norwood E. Tress for an In-Line Inserter. This invention also relates to an application of Winston A. Orsinger and Norwood E. Tress, for a Pull-Foot Sheet Feeding Device. U.S. patent application Ser. No. 608,970, filed Aug. 29, 1975. Both of these applications have been commonly assigned to the assignee of the instant application. The disclosures in these two applications are hereby incorporated by reference into this application.
The in-line inserter of the Morrison, et al application mentioned above, and the pull-foot sheet feeding device used therein, can be improved in several ways. In this regard, it has been found that it is difficult to obtain access to the suction cup and bottom roller of the insert pull-foot feeding devices in the in-line inserter. Thus, it is an object of this invention to provide structure for making it easier for an operator to gain access to these mechanisms.
Further, it has been found that when the bottom roller is used for detecting doubles and misses, as is described in the Orsinger, et al application mentioned above, that mistake readings are sometimes not obtained even though sheets are not actually fed. That is, the bottom roller and the pull foot might close, on a sheet for example, at which time the bottom roller gives no indication of a mistake; but then when the pull foot reciprocates outwardly, the detected sheet might not be carried with the pull foot. Thus, a mistake reading is not produced even though the sheet is not fed. It is therefore an object of this invention to provide a mistake detector which is more reliable for a pull-foot feeding mechanism.
Similarly, in prior art mistake detectors, detection feelers were often flexible so that they could flex upon making contact with detection points. Such flexing is intended to allow an attached moveable detection roll, or other type follower, to move still further and thereby allow sheets to pass the moveable detection roll. However, a flexible detection feeler is somewhat sloppy in movement and, over a period of time, deforms. Thus, it is an object of this invention to provide a rigid detection feeler but yet allow its moveable detection roll sufficient freedom of movement to handle undue numbers of simultaneously fed sheets.
Another area in which the in-line inserter described in the Morrison, et al application can be improved is in the mechanism for transferring envelopes from the pull-foot envelope feeding device to its chain/clamp mechanism. The problem is that it is difficult to time the insertion of envelopes into the mouths of the clamps as the machine speed is varied immediately before the clamps close. In addition, it is difficult to control the orientations of the envelopes as they are so fed. Therefore, it is an object of this invention to provide a transfer conveying system for properly conveying sheets at controlled speeds and orientations.